Drilling mud remediation

Abstract

A method and apparatus for removing liquids from spent drilling fluid solids includes a horizontally elongate separator having an augur with a discontinuous blade. The solids are heated to drive off volatile liquids, which are then collected and condensed. An internal combustion engine may actuate a generator and the exhaust gases used as a heat source, as well as electric heating elements. The exhaust gases may be introduced into the separator directly, through a heating channel or through a hollow augur shaft. Uncondensed gases may be treated to reduce particulate and gas emissions.

1 . An apparatus for cleaning particulate solids mixed with a liquid hydrocarbon comprising: 
 (a) an elongate separator defining a longitudinal solids channel and a longitudinal heating channel, said solids channel having a solids inlet at one end and a solids outlet at a second end;    (b) an internal combustion engine with an exhaust, the exhaust being connected to the longitudinal heating channel by means of an exhaust gas conduit;    (c) an auger having a centre shaft rotatably disposed within the solids channel, wherein said centre shaft is hollow and wherein said hollow centre shaft is connected to the longitudinal heating channel at one end;    (d) means for rotating the auger;    (e) means for collecting and condensing vapour and gases from the solids channel.    
   
   
       2 . The apparatus of  claim 1  wherein the hollow centre shaft defines a plurality of openings along its length.  
   
   
       3 . The apparatus of  claim 1  wherein the means for collecting and condensing the vapour and gases from the solids channel comprises a vapour outlet in the solids channel, a pump and a receiving tank for collecting condensate, gases and vapours from the pump.  
   
   
       4 . The apparatus of  claim 3  wherein the pump is a cone jet pump.  
   
   
       5 . The apparatus of  claim 3  wherein the receiving tank has an internal cooler, at least one fluid outlet, and a gas outlet.  
   
   
       6 . The apparatus of  claim 1  wherein the auger comprises a discontinuous blade disposed about the centre shaft.  
   
   
       7 . The apparatus of  claim 6  wherein the discontinuous blade comprises a plurality of paddles angled relative to a plane perpendicular to a longitudinal axis of the auger.  
   
   
       8 . The apparatus of  claim 5  further comprising a gas scrubbing system for scrubbing gases and vapours leaving the gas outlet in the receiving tank with a caustic solution.  
   
   
       9 . The apparatus of  claim 1  further comprising an electrical generator operatively connected to at least one electric heating element associated with either the separator or the exhaust gas conduit.  
   
   
       10 . An apparatus for cleaning particulate solids mixed with a liquid hydrocarbon comprising: 
 (a) an elongate separator having a solids inlet at one end and a solids outlet at a second end;    (b) means for heating the separator;    (c) an auger disposed within the separator, said auger comprising a discontinuous blade;    (d) means for rotating the auger;    (d) a vapour outlet for collecting and removing gases and vapours from within the separator.    
   
   
       11 . The apparatus of  claim 10  wherein the discontinuous blade comprises a plurality of paddles angled relative to a plane perpendicular to the longitudinal axis of the auger.  
   
   
       12 . A method of cleaning particulate solids mixed with a liquid hydrocarbon, comprising the steps of: 
 (a) providing an elongate separator defining a solids channel and having an augur disposed within the channel;    (b) actuating the augur to push solids through the solids channel while heating the solids at the same time to produce hydrocarbon vapour, wherein the solids are heated directly or indirectly by exhaust gas from an internal combustion engine or electrical heating elements or both;    (c) collecting the hydrocarbon vapour by creating a partial vacuum within the solids channel and quenching the vapour with a water spray;    (d) collecting uncondensed gases and liquids from step (c), and separately collecting liquid hydrocarbons and water;    (e) recirculating water from step (d) to step (c).    
   
   
       13 . The method of  claim 12  wherein the solids are heated by exhaust gas from an internal combustion engine which is routed through the solids channel or through the augur itself, or both.  
   
   
       14 . The method of  claim 13  wherein the internal combustion engine actuates an electrical generator operatively connected to electric heating elements used to directly or indirectly heat the solids.  
   
   
       15 . The method of  claim 12  wherein the uncondensed gases are treated in a spray tower to remove particulate matter and gas emissions.